SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4efe551a1a1d1f9bceaf0bb1f3da4f3037984df32af9ab51ca632719676427ec' 
  AND token = 'OXmOpv+kQVxg/ZJ+6k7eD7YCuJ9k0+aBKxPWUld0p5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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