SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b41fea7cf621d94c0ac57c606039e1ea7ccd0fdf16584fc21cb7b93b876deaba' 
  AND token = 'RVwYBtfXnPPJXEzbvPTAkkL4wVhQ4oRR0C8dRG4sf2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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