SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e739502a3e727ffdc5df96a2d1a4765df0ff94d77565a0995e181da387cc96a8' 
  AND token = '7EEN289auhpYVeMeIadkKi4ZBIaSNZ07p6pVT7WZ67k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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