SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18c633a34fc942e70cb417846b6497e4dc18bb3265fd4609aaa6e422a5148175' 
  AND token = 'emrWszI9PPli/DiB1dEnK3/ILQKlUcHVCEdrFtHKLKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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