SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8673ac7e20d0c0d9f4507954211b0722914404a1a6a97c4dff8dff5a6b85cec4' 
  AND token = 'Zzr4r/voXPSathrI2v8w4OSoCWc5JuDJR2gKdUj0B1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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