SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e80d234d1d56bc5e1baf790d3314049b9a382f9b3d766ba2d66885e9d7b98e2b' 
  AND token = 'USMA3MeAXVi0A72TE2WoOCdLouc80X4z/6a+JnpBM3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}