SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1737748100ed532039f339d71034e7d4177656aa78c2f607adedc60a05e0e6fa' 
  AND token = 'j7Pdm6PmxQq9j2NNV59218End9p36GD+BhrD76c6pG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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