SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e929eeec62e594b8c8ddce796ecde4260c910c83f0500d5f87f6ee371364728d' 
  AND token = '1gnH+jkdkGhVSIzVogJglGCyrnC78bevMbzuEBiS/4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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