SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f77966965430d4ba9aad14737361d72493e7763610c38432e34c4c4e436f3e1d' 
  AND token = 'LQE5095I1p31s2uYnfDGL6WxQwotXMtNZczBqs25r4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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