SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ac3383ab73c3057a94ab24b90d2e086d2b10bb32bc5112bc6331d5034975dfa' 
  AND token = 'soV+heZcgr/VpY6zq5RD0KK7v0Z6DcimCIeyFvlJyrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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