SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd5618d0b8164e4ca392642b02a5f5c06874b2b1663c6832ddaed461f92f9c5d' 
  AND token = 'y5Pa1Oq4u7g02kZPzLI5pjq4AUtcWoNNBAnwJe1GivU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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