SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9950a818cf46fc5e5dfe6306adb092a7338b08fd371d471425eedebca5e7056e' 
  AND token = 'S0nAoWiTKL3JMraZaGB9rBAkWPT70vH3A2a+X9lE8uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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