SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1402bb151cb1b3736708e354b40baad57f40ca98fcbea44ca763033bee5fd2a5' 
  AND token = 'Kl8qxPLVa32XBczoAGj5HYx2nTZJ/l12eF1/EYfjvH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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