SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b17b0f2553c62dc96484f94d806f23ce338416202f87ae364d89422228cbdfc3' 
  AND token = 'djxfiwkK6c9iYurdAo20OgVhVLHclVvK+/kPy36t+Ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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