SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd67507faaef7a4d490b49108fdcac9aeda92e916158dda2a22bdf1b4d800e2ea' 
  AND token = 'p/GSzqb2+4i34wjQRCjZm6XT9sUBzSl3qxj/xgYYsBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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