SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d4258183d7833ad1b55b4ebfed76b06439e642d9a68cc5320faf3bfdb30b9a' 
  AND token = 'uqZymeIYrf44aMRBUpHodaeqxKt8qvMtuNb49Q2xFgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}