SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c68d0641831c4350fa0154866c8c91ecb57c8cd503c2d6616a3e87bd892426' 
  AND token = 'VdOW5cWUb4q5pvXpyz67oxSzhZ0jrJBXXYA5wr+jH+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}