SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a085bfcd80edbc70b2a45ea4b899abc5a9e1bbdfdf10dcc65abde710937ac7e' 
  AND token = 'iCfVqrsKUzoYmVOaAjl7tnTNj02FpZvQAxh8vc5q8qk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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