SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fd97c2b1e50bd7227f94dfe98e54c54d77f608e23c045e936e2677c59649e3e' 
  AND token = 'pgGi9zuxaCC/zN+KVTUwRt8edneIthBxHvhtk+PPFDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}