SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '2cb7b21bb2ecccd23ae028c83c6fec0296377ee87039d98678c57ed7978a1976' 
  AND token = 'wldZv4CFWLRYotU1+vNRBGTc75D14jBlKr7HfAuQgCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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