SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58b1feeac5b16e3e6b879737790bdebbd55d7b727b3e40004ee3e696af9c8d7d' 
  AND token = 'aeRDWZotiV/anvGDSBPz5ExSrbQC86nSzie04sRqBAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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