SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '774855d82770fa3fd833a3356071094141f91e1132a0266ce9147898f5a59d0e' 
  AND token = 't5ThybqqgcJtdx7VCm/Lp9rhUwLzsw5iji0RWl0dU+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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