SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37158b30dc0d571c9a3c8837483beceb7c47aeb4ce5cf8fd70932508fbcdabf4' 
  AND token = 'OpNHrExCzv8Tordw2FmDV5B9LdAHKEShyXO8PPpUBMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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