SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b0252f78bfc23ace8cc40f23e681d2c5acccb6bbfd50bca4958848a3303b009' 
  AND token = 'YPB1E99d1ilUBlFyeZFzf2iGVPjFVArdyTIaLDHwIE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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