SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '933bafd753de6f6a381c4331965c023f4404aabb941d13c8544bd16e9318f6ab' 
  AND token = 'v736KoKCtq1/Gh5YjBFQDAikspQJ+CMGJtqUpDNtgP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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