SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a284d1837d8e66c30dc793420eedfff21e52c4631a93c3199b92b435949cdc01' 
  AND token = 'HpaEeXoVKAIwHai0flxv+KWV/KntWZAI0k+3q1CZnpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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