SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a2443b52b5b93802794388572ff9df484b68f58fbaa8e669c3f956789a12911' 
  AND token = 'JuqbcA49Y4vajKWnktOMidoDEElnCnQBNo+P64fw+4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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