SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52cdfc07d333fcb59bce1b99f7fc528f8b94e61410c1fc56b2b0533f92c5f0bc' 
  AND token = 'wtStuHZQwHZYIJPzTRSLTh2XSY9/ln2fCxHbdw8wHZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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