SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7ffe84130d1f073b0a19712cad559a56b11a49efa787dba64e97590b102f500e' 
  AND token = 'QvygMPh7/b0gYu1AxyDNF9IRFG4htN0M8DbO7VzTYJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}