SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12a97a764c2bc5a1aad6d339b890fa856fdc5d377cc4dab072cb0e08af4a0bec' 
  AND token = 'OEdoT7o9/TuGcxMyGJNhPmltD0ofjhgCE4stC+wCG2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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