SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed58a5a946475683a386ff8172593847bb2bf85cfd06b93342a655c06e56e6f3' 
  AND token = '0sZ9/spASQVQLPprB00uD4t/NImQScumr2HQqIBvelM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

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