SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e887ae107de01d1c5ec2c80b063fdf30ab983e833ef0189e7f76b949987393de' 
  AND token = 'Nf7c//5R62iXXl14QyXpfaOjTxaxNkmkO3TNzcpGACw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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