SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8151c2d78d0eb5fe2539135d2e19c1ee7cd8cf715826b52f5fdfbd11965581c7' 
  AND token = 'LZlElkgnFaFBYHr5HuGnZXN644E2W6hhYvIA6lPoYoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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