SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c952c83af2d1dd6871b0028e1d603a6b25bcc858b5dbaeff7b8d7baf43bb533b' 
  AND token = 'WwCu2Bz6mhUVOcvWEgMXxzd8UlKD4NucJZD6qdi+Jm0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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