SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10e1bc672a08bf9a2e60eda9e6e67081cf51ecec951addc80c5a1ef67c231789' 
  AND token = 'FRJhVcx1B6y8Co/JyocK5JLYvrW0pi/JIqqlsHhsjG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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