SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17aff87c69e9838ddbc247164e6450c08002fab91b2d652dddbd12d00d79216b' 
  AND token = '1rQ7cDP98YJFK5GL7h+iyxQcpQmx7vTUG1ItNgOxGv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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