SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99ffd092787bff1f5bef38834e132310a7b941dc980c8aa86e3c0842ef016beb' 
  AND token = 'r/Qfn+BdomQnKxSrjjJ3f8MTOIFPiU6lCMyPTT8wpyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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