SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df5bedc226141205751f5ad06d8d87dbb337fc8b8df538f341a7dbfc38b802d9' 
  AND token = 'WF+nz1qDqAlEJwWQCwry8Ht1jbwrSy8BpA4jBw+siq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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