SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1052d244d988c75c08afa1795945d7c52c1e29081837c0a7329d4d23403895b0' 
  AND token = 'oKafkoOnlY461fVne2bMlPrk+xwXmbLSOd9eSIlsMBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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