SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '469313f670f2bd80f99d2d3933727102fd76593cc5139da0cc06a1925bf1b8e9' 
  AND token = 'ev2QVKTBgb/JKOV/qKuU8LfHBiMAowI19BY9S4KjgUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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