SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6064f23c6b8ccfaf77451a7e87c175921820f16fec78828cd2cb6093a8c32b53' 
  AND token = 'putjmIed9IpASLXhH1j3WzO188eP6KnkMJ0Vrg+HdQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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