SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '82016aba3761930373038329db1f0746cf0ccbb78af50bcac2eea6f4b429b875' 
  AND token = 'sPTq6lKt2lx3MFrSHnzRsBvMKhrBGu6UqyA4epx01b8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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