SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed7a3213fb7393480432d39bd21aa74894874a9181fa9bf27f5715f1adf4891c' 
  AND token = 'sLLhuOQ6ymnhDk8a3MFj/S4LxCYGaQ55+5Fkuhal/IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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