SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97987bcfb4045886ecb25e54036cf3fccbf93ba26f53e21062e114bd059dff18' 
  AND token = '6COEeD+xFPma4LStBjXUGsPd34RpqfPQZHW1eA4a+pY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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