SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f5306cdb950db3b755990bab7f1f56c7e3bf7d4c75113a2ceb4eac543bb2ddb' 
  AND token = 'T3YkHoE4Rwii8moVUYMZ6YNyQc51UjXrR8cyBfsDibw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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