SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f2c654c759a3653deada838b0792bf879f8fbd0c26fd5f3777a480cee73391c' 
  AND token = 'rznjkL3FglJXXRmVYGQ3TQz/w1+rJs/cfFvyMAweMII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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