SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8cbf2910fe77c8a92fcc4cc3899af6aa2c5135fb46dec5b633c44a63a48d539' 
  AND token = 'faZ8JEqFVIZjAVv/YSoXsKB+ruRg2V5ZGurzI93jeww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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