SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9011612542279ca9ce6ef700270c8d21f68a08b0075e6b6584dfbabe74c8256a' 
  AND token = 'MoBSdAF2dLNRYXG7ktYHTiSaSX4JxTxwOE65jmqbUms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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