SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '017c7090aeb400c3a068487ff80e3fd964e2723eb801179482169967242a851b' 
  AND token = 'P+9nTnQbA6jfpqz5iJG05Nl1S1TSI94f/FAFIsp9aWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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