SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36c363309e06786f6d99011e3bb8364d4d048aa72ce3243d778096f7f90718ca' 
  AND token = 'yRiJk1aIDB/i7GRtURSoiPiaZwYDVz1xZNj1BCR/Pic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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