SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfe02213ab2c27950608f5526fc0ad385a8505c4ec66ab791b9f29b1ab1afefc' 
  AND token = 'kszPojrVQvgvEhDYRuxCbP1u+8lkoWEFMV8O9wTPiTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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