SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '863276f07a0e10d9d80fd861d3b54220e16552df6c1919c66198cb396a87f6fb' 
  AND token = 's3BCSPUXWezddB6OgwwnFSjmMVy9yQvDVfX61cADX+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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