SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2bad75063244e43fc1de3da26d0973cd6dfa57742d35db943038bf746c5bc11' 
  AND token = '2dmswtie58KKGcqRf12QrBOoxTN4QhPpMntHlTFZbZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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