SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58d54c63858d4ceeeb0808e95f776410ef423ad7e8f47dc91e2d82b4b67c78a4' 
  AND token = 'e7qqDgflctD4B8DCItM3R7WiTFklXRMeL1YLhhoPulU=' 
  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"
    }
  }
}