SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6db7f628e9b3edeec9ec2b2185c3ce7a7b0543a02f112801592597c8cb80c69a' 
  AND token = '0dH1bNamAv26IJLHYyLz+oc7W4iz2I/d5quJV+uAs+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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