SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaa8c751c91e20a6be620ee23f9fde5bef9117964cceedd9306cca3b1703a17b' 
  AND token = 'jZiG1YbL9/avqm6YyzR3XnYw5aKlJ77oqkhcShz1YvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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