SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9e86b2ed3212a689d98820391eb54bdfe978fbed58223ed75a455c98d04e8fb' 
  AND token = 'yGmCxYzgdEMYB/K27hai4qdgAxZ3tCZBywuBkHQPU6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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