SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c9d4aa702781c52c33cde77d8ae3acdde6c4ca5c8640e3a56d4889831b418dc' 
  AND token = 'Z0UP2dyeAeh8wzyikUwhFlIjt34qiQNspj4YKGAyUQE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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