SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0d95a862472a9ce85524d9b9d25b6d65ade063da6022c2724628904d9408ff3' 
  AND token = 'reZWhJOlmfFf5xQQ7MCG9anRtRAyzhLws0E2AXxLxsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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