SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bede7783a746d1f6f0437b02af9635f4db389f5734acda7aea8880e5cda2a163' 
  AND token = 'oJT8ofC28LMFDqKxVRC5AOunwWGxFQfyfoZdLcFshlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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