SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '881fe5e386f5665cd77c9d2eca841420d2aef5fae74acac343b43d0561d34e20' 
  AND token = 'j0BPbvJSBSYJdHOH1EL20egH1eELVTQnElZN7LVurPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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