SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53b22274c5ee986690997237f77b829fdefd4c8574270e818eafd2dcd3765af5' 
  AND token = 'GKgL3kgAIjH+NxlJlhPrC4oAHTjN5EYKkWnbtP+yi1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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