SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '345ac3f15ebf09701caeb7282c1169c1dda6865b73c5f853ef5776153bcbd3d0' 
  AND token = 'bWNa+ynsOgTDcORBXzUtNylIBPUeAsuAoaoZr8PbgOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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