SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a2d087439cac985d750d5c1191dbb1866c14112aa779d73cbf6890629daf043' 
  AND token = 'zdpqhAHKyJLPq4aIjm3H/mPgnQdHxszuCE6vi18Wl+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}