SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6927b81128beb7c355d1c5670e2a32bc4db80e6f1d6098aec6b028e5f2381143' 
  AND token = 'p6QQ+x7dzrwAGcS03Md0TpvdnTPCK/wJwgZkJOh5ETo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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