SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f33c76d372c99bb2d5c0e3847faec0b595e66feec7e0aa293e7b394e7bd3da3' 
  AND token = 'EAZ7NOzi9RZwLJvYwFfrMgExxduu61sboiG6vI4o8s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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