SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce37c50b13b9dda3229c362b264712f7219ffe442fd5e8e04fe92e9e3154ab4a' 
  AND token = '4ZcS7gTUXzMTOr1m1Y8KD5JD5JG4O+kMT7ghD23HDog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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