SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce5f3adee378277525fc60e3ac58b399a4d990b4ebabe47aa906b37beea28942' 
  AND token = 'C3Nf7qgkUrL4vkfDhKZyG6P8GiBVPYRihXcv8dwXIYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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