SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c111bd41a66700c3fd9809269ddae1bbfdb4e9af3808436923df27ac1bf9b01' 
  AND token = 'fmzEzgoBz0voEJX1nzDul3Qys3rDGzU2Iy7MS+BDwhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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