SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f3308cabaca74fa9be59e1ce49478129593b11ec29be8b75d94af298de095ba' 
  AND token = 'atA6awEVQgKeRQJA0Ys9jip5R/JK93Dlbv2AJ12SPlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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