SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '368ad5ad91801186881f3dd581b4cb2e7267196c2937c9a203a5a3ca6028a3d8' 
  AND token = 'i9LsEOBx4JPuB0JLghwNAYvyyWTkd/WtDnvsI9B+ntg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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