SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d96c0571689bf4fc152b975586a50c5c7562247849336fa52abc1cd7140893b' 
  AND token = 'b6YYOtnOea+GUoZEHIcltSBM85ZJfgFDgqq1ADpKM7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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