SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a89a7c0d5b212bab0d43919bc60fe5b13674ad2cdaf5218602bd146a857ad994' 
  AND token = 'syK7rrjlBzVbXys7Z6ixqaj8J2FLQ+pc7PctPg8u/mY=' 
  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"
    }
  }
}