SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c41b476288354b0352d927b8e2045a2826a0340104d3afeb41fbddc1d856ff83' 
  AND token = 'MF06mFGuFeNtsmHY3w6PwulmqgPM9v5FErggnA369y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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