SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4247fa323536a677e3878faaf2e4f67877c0da6d5d96794bf523ca6be8c9f989' 
  AND token = 'G/BCme6Mij3eG1DJUFPGLsC9mLIZJelnqyVgvuK1baA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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