SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b746bc577c1a81772e4bef9dfb0c4d4cf0b2dbaf97ec297e466e711f53255cd3' 
  AND token = 'DAp41cEP31j7I1TpNUhpQOQOtIA36jPGT4fFB9pNVKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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