SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2601b21f2d81282608202429bce6556917d14deb3ccd28b974422481345b1f2' 
  AND token = 'BM+nKfZowGq95e2CW8QdPQkRTthGJoiJfBblHgB6T90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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