SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6eba3a64d2c9e98e39f81836baf2830111a2537049bd8188b8b1dab469e9254' 
  AND token = 'xS+3eVJUfIuSBa++YU4q2QXGtX7F4XEV9GVIVS5MtP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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