SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eafe46212811680fd52b802c661c0d34af154078bb5f5a71d400c472a549a7a0' 
  AND token = 'y1KK4qY5mdQ6ufzOvStWOZOTvw3yDZrhe/VM5HQm3EU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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