SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a720ca1b70649ac59125553743e80160963066bd9d81571e5a3677d168eeba0' 
  AND token = 'SFKUlyGy3yU1YSai1EIvq2KZWpdLio2J4TzqQ1hJjJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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