SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b554a7ad00149c243108ba28cb8ecf2e6f7a3dcbbcbaacc6f528d0fe767bc183' 
  AND token = 'mrqa32EOth6GLfr6FlXnvSyw5/UY8ZBFP4We7Efhuvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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