SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2dad387d01c2e41af7009c75a2a39be39e3309228f14568d2e726e647bfef34' 
  AND token = 'HafRvJx9jpgM4TNVcMoWJRlYPKPFwpOn0cQ7Z9kpXdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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