SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '10539ac37c01d6cba1fa4cbb1737d19ed1bbfdf3012d8b28ee31bb1f7c81a080' 
  AND token = 'VS+O/KvRRQOK+anFhAoffNEwkBEoyMRqEXYxMq1YLIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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