SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0f378a2a75607b6d62cc0309b03e6155dea3601fab8e333b30387c66d20d2d0' 
  AND token = 'UXCkvEopcBYpjODFgKGiwTMBC42PnMoG+b1Vh9uwWLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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