SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6303d1ade53e23e2b73bc3f091f2ffa9585e002d91cad50338823d687aa1f56a' 
  AND token = 'kTH4QOp7uUHm/QdP8FOBKv6RsmvkravaYI6/3XqOqVM=' 
  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"
    }
  }
}