SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ca82a9f5d4c09c59ba99a7c1626d335af4937645dc100ad0fe358931f2ecca' 
  AND token = 'qZ+dMZOkCi6JT+gwUVlwefh7vyS63dX3xglWq/YRp+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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