SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fcbd0d1af9d47eb48c7eb5645a9f962c284694ef10a1da86039b5f8ca1fdffe' 
  AND token = 'o1ChnSkHKsLQ5hpqvmmIhY31vRbRJ/wBbqD9U4EIPeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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