SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f96431961a99db5f8340472fd7ed03626ad22e5731e19999f58803215f3f2a51' 
  AND token = 'wodzPmdvRL4JrlEeZyVc+yrLIMthFvloi1Jrz4bGzc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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