SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eb4cf91ab5d0f3eeb2622d7ffbee95a988ea32bb2dacfdd665f157c9c159186' 
  AND token = 'KZ/R5AekQUNEdXKkyO78L8xFRSeTJ2Eg9emRrnF2UmM=' 
  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"
    }
  }
}