SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b24f5c61b11ebf644e558dfeb462d84a797dc5a6edb049819275dab03d97c449' 
  AND token = '31O5BHe3Zq0xaW8EQSkWjc4j5MAiNyd7mxpzXlcT1c0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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