SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3dad9bdb673b53169ee80ef874f0ed91bff7c8aa10689467fbe45778b5a5e26' 
  AND token = 'EWkCo+YajOEOzQBKSZ7qCthiSCme5FOwt58STwRR6i4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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