SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87eda2395f5f82900be8c2bf125b3a7f3e8a039b746b1df38375d8ad59639c3b' 
  AND token = '+DS3PZGAQx4IVKSYBzzazVsUV30Bvs0h9BwGE1VSEy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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