SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '979fbec08d37cffd256f440d40e22b19dfb1b6ace5ad76d95ee183b280b11a9e' 
  AND token = 'a3m+fDuvRQ9cX5+6bI2RHavF0QBaxf/EeTdtFTNTTYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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