SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0197dafda15da8e1e646ab8f5a51f5480c3e756b213f2cf0d82631235d74d3f9' 
  AND token = 'rHEZR9Q58k4W2qvTCPjl7FySOtAlPc3y4XT1n6Hj/0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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